The present invention relates to design assistance method and design assistance apparatus therefor, and more particularly to computer assisted method and apparatus suitable for arranging drains and vents in a plant by a computer.
In a layout plan of layout objects in a plant (equipments and pipes of the plant), a method for automatically generating connecting paths in a spatial layout plan for automatically determining optimum piping paths of pipes in accordance with arrangement data of equipments in an area of layout objects and design reference data is proposed by JP-A-60-79470.
JP-A-61-213969 (corresponding to U.S. patent application Ser. No. 838,957 filed on Mar. 12, 1986 which issued as U.S. Pat. No. 4,789,944 on Dec. 6, 1988) teaches layout of pipes while a restriction area for the design objects (an area in which the design objects cannot be arranged) is graphically displayed on a screen of a display device.
In the plant, vent pipes and drain pipes are arranged to discharge liquid in the plant from a system. Usually, the vent pipes and drain pipes are arranged in places which allow easy discharge (vent or drain) of the liquid in the plant from the system. For example, the vent pipes are connected to locally high areas in the plant system and the drain pipes are connected to locally low areas in the system. However, the design positions of the vent pipes and drain pipes are determined by a designer while he/she watches design drawings and data. As a result, a long time is required to determine the design positions and there is a risk that the pipes are not arranged in right places.
In the computer assisted design apparatus disclosed in the above references, no effective means for setting the places of the liquid discharge pipes such as drain pipes and vent pipes is taught, and the designer has to determine the places of the drain pipes and vent pipes while he/she watches the drawings and data. In the prior art, a position of a stay area of the liquid to be discharged, in the plant system at which the drain pipes are to be arranged cannot be properly determined. The liquid stay area may include a vent stay area and a drain stay area.